package day05;

import java.util.Scanner;

public class txt15 {
    public static void main(String[] args) {
        Scanner s=new Scanner(System.in);
        int month=s.nextInt();
        int year=2025;
        switch (month){
            case 1:
                System.out.println("31天");break;
            case 3:
                System.out.println("31天");break;
            case 5:
                System.out.println("31天");break;
            case 7:
                System.out.println("31天");break;
            case 8:
                System.out.println("31天");break;
            case 10:
                System.out.println("31天");break;
            case 12:
                System.out.println("31天");break;
                case 4:
                System.out.println("30天");break;
            case 6:
                System.out.println("30天");break;
            case 9:
                System.out.println("30天");break;
            case 11:
                System.out.println("30天");break;
            case 2:
                System.out.println(year%4==0&&year!=100||year%400==0?"29":"28");break;
                default:
                System.out.println("输入错误");


        }
        }
    }

